Simultaneous Determination of Cu(II) and Mn(II) with Dual-wavelength Dual-indicator Catalytic Kinetic Spectrophotometry

A new dual-wavelength single-indicator catalytic kinetic spectrophotometric method for the determination of trace Cu(II) and Mn(II) in HAc-NaAc(pH4.5) buffer solution medium was studied.The method was based on the Cu(II)and Mn(II)catalyzing oxidation of methythlene blue and rhodamine B by potassium periodate.The absorbance of catalytic and uncatalytic systems was measured at 660nm and 540nm.Under the optimum conditions,the linear range of the determination of trace Cu(II) and Mn(II) were 0.0050~0.025μg/mL and 0.0010~0.020μg/mL.The detection limits were 3.3×10-10g/mL and 7.6×10-11g/mL respectively.The method was simple,high sensitivity,and good selectivity,the method was applied to the determination of trace Cu(II) and Mn(II) in hair and rice with satisfactory results.